Barilius is a genus, not a species. They name "stream barilius" is just a common name that appears to be nowhere on the internet. That one closely resembles the Barilius Ardens. However, three main species of Barilius are commonly confused, ( (with little to know clear differences for identification. Originates in east Asia, namely India. They get 4 inches long.
Sorry, I searched for 30 minutes for this and that is all I could find. Fortunately, even if it is not an the species Ardens, most of them I found get around 3-5 inches.